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Biomedical subjects

K A Kooi

Publications and source records attributed to K A Kooi.

At least 19 recordsLinked to original sources
PubMed1986

Visual evoked response in head trauma: pattern-shift stimulus.

Studies of visual evoked potentials in head injuries have all utilized the flash stimulus. We studied the efficacy of monocular pattern-shift visual evoked potentials (PSVEPs) in eliciting residual dysfunction of the visual pathways in 33 patients 6 to 24 months after head injury. Those with ocular trauma or ocular pathology were not included. Abnormal PSVEPs were seen in one-third of 33 head-injured patients. Only 1 (11%) of 9 patients with mild cognitive impairment had abnormal PSVEPs compared with 7 (39%) of 18 with moderate and 3 (50%) of 6 with severe cognitive impairment.

Adolescent↗
PubMed1976

Fourteen and six c/sec positive bursts in comatose patients.

Of ten patients with Reye's syndrome, there were five with stage II or III coma where EEGs revealed 14 c/sec positive bursts in a background of diffuse delta waves. Positive bursts disappeared upon EEG improvement in two survivors and when the EEG became nearly isoelectric in two other patients. Although 14 and 6 c/sec positive bursts are seen commonly during sleep in normal young persons, their occurence in association with diffuse delta waves in acutely ill, comatose patients has been rarely reported. It is not certain whether the present findings should be regarded as selective preservation of a type of sleep pattern or whether there are special factors that enhance positive bursts in stage II or III coma of Reye's syndrome.

Adolescent↗
PubMed1971

Visually evoked responses in multiple sclerosis.

Visually evoked cerebral responses (VERs) from the occipital and central areas were compared between 50 patients with multiple sclerosis and 50 control subjects. The average peak latencies of four occipital components (OII-OV) and two central ones (CIV and CV) were significantly delayed. In no instance was the amplitude significantly different. Routine EEGs were either entirely normal (16) or showed only minor findings (10) in 26 patients. Of this group, nine showed abnormal VERs. Seventeen patients had clinical symptoms or signs which pointed to spinal cord involvement only; nonetheless, eight in this group had abnormal responses. Inasmuch as changes in visually evoked potentials are not directly dependent upon the presence of a demonstrable field defect, the technique may be useful in detecting otherwise occult cerebral lesions.

Adult↗